This invention relates to mechanisms used in conjunction with sewing operations, and more specifically to a fully mechanized method and apparatus for automatically transferring and inverting pocket-like fabric work pieces from a first seaming station to a second seaming station with an intermediate inverting operation.
In the formation of certain garment subcomponents, illustrative pockets, collars, cuffs, epaulets, cap bills, and the like (hereinafter referred to as pocket-like work pieces), it is known to stitch together a plurality of superposed plies or layers of fabric together (sometimes with an intermediate stiffener layer such as buckram in the case of collars, cap bills, and cuffs). After the layers are assembled by means of a first peripheral seam extending around some, but not all, sides of the work piece, the work piece is inverted. After such inversion the first seam initially connecting the layers then defines the outer margin or edge of the work piece. The inverted layers are then subjected to a pressing operation following which the pressed work piece is subjected to a second seam parallel to the first seam through the doubled-over plies adjacent the margin or edge of the work piece. During and subsequent to the inversion operation it is highly desirable that the initial seam lie exactly on the marginal edge of the work piece in order to result in an eventual garment of high quality. The above-described procedure is commonly referred to as a "stitch-turn-stitch" operation.
Previously the above-described inverting operation has been accomplished substantially by hand. In the forming of pockets as taught by applicant's earlier U.S. Pat. No. 3,789,781 to Carson et al, once the first seam was applied to the superposed fabric layers, the operator manually placed the pocket on an upstanding mandrel 150, whereupon the operator manually turns or reverses the pocket thereupon. The manual inversion of the pocket work piece is very time consuming because in addition to totally consuming the time of an operator, it is very difficult to align the first formed seam exactly along the work piece edge. Other examples of devices in the prior art which are intended to facilitate the forming of double ply pocket-like work pieces include U.S. Pat. Nos. 3,125,261 to Arbter; 4,213,547 to Connor, Jr.; and 4,427,139 to Depriest.
Although the invention will be described in conjunction with the production of garment pockets, the basic concepts of the invention are also susceptible to other applications of the "stitch-turn-stitch" operation, such as collars, cuffs, and the like. Briefly stated the present invention is directed to a method and apparatus for automatically handling the pocket-like work piece from the time a seaming apparatus finishes the first stitching operation until the inverted work piece is ready to have the second seam applied. During the interim period, the work piece is inverted and pressed. In addition to the obvious labor savings, quality is maintained as the machine is so designed as to ensure that the first seam, when inverted, lies exactly along the marginal edge.
Generally, the present invention is directed to a method and apparatus for forming pocket-like, multi-ply work pieces which are double seamed along portions of at least some, but not all, sides. The apparatus includes spaced sewing instrumentalities, one of the sewing instrumentalities applying a first seam to the work piece and the second of the sewing instrumentalities applying a second seam to the work piece after it is inverted. A pickup mechanism grasps the uppermost ply of the work piece adjacent an unsewn side and transfers the work piece onto a spreading mechanism which is inserted between the separated plies of the work piece as it is removed by the pickup mechanism. The jaws of the spreading mechanism are then spread vertically to space the plies of the pocket-like work piece, whereupon the jaw mechanism is moved from a loading position to a discharge position in alignment with an inverting mechanism. The inverting mechanism includes a split plate mandrel insertable between the jaws of the spreading jaw mechanism. The mandrel engages a sewn side of the work piece as it enters, inverting and transferring the work piece from the jaw mechanism onto the mandrel. The expandable mandrel is then spread laterally to form the correct pocket shape, set the first seam along the marginal edge, and retain the pocket on the mandrel assembly as it is retracted from the spreading jaw mechanism. The work piece, while still mounted on the expanded mandrel, is then passed through opposed pairs of counter-rotating rotary brushes which smooth and straighten the pocket on the mandrel. The inverted pocket or work piece is then presented to the second sewing instrumentality for applying the second seam.
The pickup mechanism itself is adapted for use with pockets of a type in which the unseamed side is comprised of non-aligned edges. First, the pickup mechanism includes a sensor which identifies whether the upper ply extends laterally beyond the lower ply or vice versa, and transmits an electrical signal representative thereof. A pair of vertically spaced upper and lower clamping fingers are then moved from a retracted first position to an extended second position at the loading station. The clamping fingers are pivotally attached at one end for moving the free ends thereof between a clamping position, an open position, and a first or second insertion position. The lower clamping finger is then controlled by the aforesaid signal generated by the sensor as it is moved inwardly. Thus the lower clamping finger is caused to move along either a first insertion path which corresponds to a receding upper ply edge, or a second insertion path which corresponds to a protruding upper ply edge.
The spreading device includes a pair of vertically spaced, horizontally extending jaws which are moved from a first closed position to a second open position. Once the pocket is loaded onto the spreading device it is rotated from a loading position to a discharge or inverting position. The inverting device includes an expandable mandrel positioned adjacent the spreading device when in the discharge position. The expandable mandrel is then inserted between the jaws of the spreading mechanism. The expandable mandrel includes a pair of substantially horizontally planar, juxtaposed plates, one of the plates at least partially overlying the other. The mandrel assembly is moved forwardly into an extended position between the jaws of the spreading device which engage and invert the work piece, and transfers it onto the mandrel assembly right side out. Simultaneously the mandrel control means also expands the plates laterally from a collapsed position into a laterally expanded position to spread and stretch the work piece.
The aforesaid mandrel assembly is adapted to be moved between a first retracted position and either of two extended positions. The length of the stroke of the forward thrust of the expandable mandrel is determined by a pair of pivotally actuated stop members which are electrically controlled to move between an upward position which determines the shorter length stroke and a downward position which determines the longer length stroke.
As the plies of the work piece are spaced apart on the spreading device a laterally expandable seam locater lever engages and maintains the first seam exactly on the marginal edge as the work piece is turned right side out. Upon inversion the work piece becomes mounted on the mandrel assembly with the first seam defining the marginal edge thereof ready for application of the second seam. Prior to the removal of the work piece from the mandrel and the second seaming operation, the mandrel with the work piece mounted thereon is passed between one or more opposed pairs of bristle covered rollers which iron and smooth out the wrinkles.
It is therefore an object of the present invention to provide an improved method and apparatus for inverting pocket-like work pieces subsequent to a first and prior to a second seaming operation.
It is another object of the present invention to provide a method and apparatus of the type described which is fully automated.
It is yet a further object of the present invention to provide an improved device for identifying and picking up a double-ply fabric work piece from a support surface, even where the unseamed edges of the work piece are not aligned, and mounting the work piece on a support of the type which is inserted between the plies of the work piece.
Yet another object of the present invention is to provide an apparatus for inverting pocket-like work pieces about a horizontal seam while maintaining the seam contiguous with the edge of the inverted work piece.